1. Field of the Invention
The present invention relates generally to an orthotic support device for the forefoot, more particularly to an orthotic apparatus used to align and lock the first metatarsal in a plantarflexed position.
2. Description of the Prior Art
The foot is the base of the body, and for many years people have been trying to find the most effective way to stabilize the foot. Most of the efforts have been focused on the subtalar joint. However, of late, many ideas have been brought forth to bring the first metatarsal under control thus creating a stable foot and allowing control of the height of the arch.
The first metatarsal creates the distal part of the foot arch and has range of motion at the first metatarsal-cuneiform joint. This range of motion is often excessive; there is a condition known as functional hallux limitus in which the first metatarsal is hypermobile, raising the head of metatarsal bone above the base of the hallux, creating an inability of the hallux to dorsiflex, or bend while walking. The condition also creates a collapse of the arch, as well as, over-pronation, which can cause a wide variety of common foot, knee, hip, and lower back ailments. A solution to the problem is plantarflexing the first metatarsal so that the metatarsal head is lower than the base of the hallux, allowing free and unobstructed range of motion of the hallux, at the first metatarsal-phalangeal joint, which controls the functional hallux limitus. This is often attempted with a medial cut-out of an orthotic insole, either custom made or prefabricated. The orthotic device with a medial cut-out allows the head of the first metatarsal to drop lower than the other metatarsal heads, creating a steeper arch on the distal side, while the rest of the orthotic lifts the proximal part of the arch. Another pronation control device is the cluffy wedge, (U.S. Pat. No. 6,170,176, U.S. Pat. No. 6,874,258, U.S. Pat. No. 6,938,363 to James G. Clough), which pre-dorsiflexes the hallux to the top of the first metatarsal head and pushes the head down, plantarflexing the first metatarsal and keeping it from collapsing.
Many podiatric patients that could benefit by using an orthotic insole are intolerant of having the bottom of their foot manipulated, precluding the use of an insole with a medial cut-out. A major limitation of cluffy wedge embodiments and method of use, is the lack of space in conventional footwear to accommodate the wedge device and a permanently dorsiflexed hallux.